[OceanOfLight]

Sorry if I intrude, but I got the same problem.

I think you misunderstood the issue.

The real problem is that to actually make the device enter Low Gain mode, after every reboots you have to go under the Gain menu, and now there are two possibilities:

1. if you were using High Gain mode, you only need to switch to Low Gain mode.

2. if you were already using Low Gain Mode in order to make the device effectively go in Low Gain, you need to switch from Low Gain to High Gain to Low Gain again (as I show in the attached video).

So, to be clear from the start, the real problem is that, if you shut off the device while in Low Gain, on reboot the device will operate automatically in High Gain without actually telling you that. (It will in fact show the "L" on the display and Low Gain in the submenu, but as I said, it will effectively operate in High Gain).

So, this is not a problem for people who use High Gain only, but it is a really big one for people who use Low Gain instead, cause with low impedance IEMs after every reboot (when I forgot to fix the problem with the abovementioned procedure) the volume will be so loud that it could potentially damages the IEMs (and me).

So, to reproduce the issue (for your engineers) let's go by steps:

- The BTR15 is turned off and not connected with USB to the pc.
- Attach an IEM and turn on the BTR15.
- Connect the BTR15 to pc via usb C.
- Go under the GAIN submenu and:
1. if you were using High Gain mode, switch to Low Gain mode.
2. If you were using Low Gain mode, switch from Low Gain to High Gain to Low Gain again.
(you can check that the change is effectively happening because you will hear a popping sound in the IEM when switching from one mode to another, if you are not hearing it, it's not really switching).
- Now the device is finally set to Low Gain.
- Listen to a song with at a volume you think is right.
- Reboot the device and wait for 5 seconds.
- Now the device will operate in High Gain again (despite showing the L on the screen), you can confirm this by listening the same song (at the same volume). Now the song will be way louder.

This clearly indicates that the device reset itself to High Gain (on its own) after every reboot. To have another confirmation of this, go now to the GAIN submenu and switch from Low Gain to High Gain. Now listen to the same song again. There will be no audible change in volume (it will still be as loud as before), because the device was already functioning in High Gain mode before you actually switched to it.

The heart of the matter is that the BTR15 will set itself on High Gain mode after every reboot. The only way to set the device to Low Gain is:
1. if you are using High Gain mode, switch to Low Gain mode.
2. If you are using Low Gain mode, switch from Low Gain to High Gain to Low Gain again.

This is the only way to set the device effectively to Low Gain, but as for now, this procedure needs to be repeated every time the BTR15 is rebooted.

I really think this problem affect every single BTR15 unit, but only the people that use the device in Low Gain mode are able to realize that.

Now, if you can't replicate the issue and fix it, I give up.

And I'm now realizing I ended up writing a manual on this simple issue. You should consider gifting me a KA17 for the efforts.

I decided to repost my report, because I suspect Fiio didn't see it (too many posts on the thread, maybe).

Can you please address the abovementioned issue on the BTR15 with your engineers?

If you already seen it and reported it to them, do you have any news about it? Thank you for your time!

 

[AudioBomb]

Just read in some forum that BTR7 and Mojo 2 sound the same. lol. Never liked Mojo 1, really.

 

[Chris Kaoss]

Just read in some forum that BTR7 and Mojo 2 sound the same. lol. Never liked Mojo 1, really.

Sure. ^^

 

[sofastreamer]

Just read in some forum that BTR7 and Mojo 2 sound the same. lol. Never liked Mojo 1, really.

i honestly doubt that. The THX Amps wont be able to give a holographic soundstage at all. while the mojo isnt good in that too it is does a much better job than any thx output stage for sure.

 

[sofastreamer]

Dear friend,

Thanks for the kind feedback. We have report to the quality engineer for check. But we fail to reproduce the same problem currently. So it may still take us some time for locating the issue.

Best regards

Hi Fiio,

maybe i have some news that could help your engineers:

i was experimenting the last couple of days and found out, that when the BTR15 is connected to my btr30 pro via bluetoth ldac and my S20FE has Bluetooth enabled the permanent reboots occur about 4-5 times per hour. It doesnt matter if the BTR 15 is connected to the samsung as a secondary device or not. As long as the S20fe has bluetooth enabled, the issue happens.
But when i disable bluetooth of the samsung while connected to the btr30pro the reboots only appear about 2 times in 12 hours.

So i assume reboots are triggered by any kind of BT packets devices send from time to time when looking for other BT devices. Hope that helps.

 

[AudioBomb]

And today my OTG cable finally arrived. Big difference, even because I just had aptx (non HD) on my old smartphone. Everything sounds cleaner and clearer, the difference in treble's definition and airyness is immediatelly perceptible. Exactly as I have tried from the PC when I've produced the intro of a song with it. PC sounds better due to be using Fidelizer PRO's purifier and IEM's psycoacoustic corrections from Realphones. Xelento is also calibrated from Sonarworks, so yeah, from Windows it is a different beast. Even though Antelope Audio Zen GO after a second test sounds much better than BTR15.

 

[AudioBomb]

I agree with you on the filters. I did further testing, and the increase in soundstage and overall pleasantness that I was talking about is way more prominent on my planar IEMs compared to my DD IEMs.

 

[AudioBomb]

It's the oposite on my Tesla. Something's really wrong with the fast filter. What doesn't seem to make sense with other IEMs, but thr truth is that it does. The hybrid filter should be supposedly "better" but seems that it reacts differently with multi-BA and different types of dynamic drivers. With my tesla it changes everything except soundstage of any sort.

 

[w00ha]

I decided to repost my report, because I suspect Fiio didn't see it (too many posts on the thread, maybe).

Can you please address the abovementioned issue on the BTR15 with your engineers?

If you already seen it and reported it to them, do you have any news about it? Thank you for your time!

I received my BTR15 today and can confirm this BUG...very bad for my IEM's!
Sometimes with very loud clicks and plops between switching Gain mode.
At the moment I leave it on "high".
I'm on firmware 3.5 / Android.

Please FiiO...fix this ASAP

 

[stuck limo]

And today my OTG cable finally arrived. Big difference, even because I just had aptx (non HD) on my old smartphone. Everything sounds cleaner and clearer, the difference in treble's definition and airyness is immediatelly perceptible. Exactly as I have tried from the PC when I've produced the intro of a song with it. PC sounds better due to be using Fidelizer PRO's purifier.

Which cable?

 

[XaFFi]

i honestly doubt that. The THX Amps wont be able to give a holographic soundstage at all. while the mojo isnt good in that too it is does a much better job than any thx output stage for sure.

Hi, You are confusing yourself. Amplifiers, including THX, have nothing to do with whether they can deliver holographic or 3D sound. It is rather a matter of the recording source and its particular software algorithms. THX is a quality standard that provides the best possible sound experience with the best material available. The quality is indisputable and covers all types of media, be it for gaming, cinema, multimedia etc etc... Greetings!
.

 

[AudioBomb]

Which cable?

Some ordinary cable from iJiZuo. Got it from amazon.de

 

[AudioBomb]

Hi, You are confusing yourself. Amplifiers, including THX, have nothing to do with whether they can deliver holographic or 3D sound. It is rather a matter of the recording source and its particular software algorithms. THX is a quality standard that provides the best possible sound experience with the best material available. The quality is indisputable and covers all types of media, be it for gaming, cinema, multimedia etc etc... Greetings!
.

There must be a difference even with my Xelento, because today I got back to my Antelope Audio Zen Go, did another A/B with BTR15 and I was wrong from first impression, Zen GO sounds miles ahead in every aspect. Treble has much superior definition and extension and soundstage/imaging are on another level, as is claritry. There's no more confusion about this. Just if I could have that experience on the go :S

I think I'm going to order Antelope Audio ZEO mini DAC, for the sake of comparison. But I'm still divided between BTR7 and ZEO. Since ZEO is powered by the same 64bit Acoustically Focused Clocking and 130db dynamic range DAC as Zen GO, I have a feeling it can sound better even unbalanced (big mistake from Antelope though). But I think BTR7 amp is superior, so not sure. After all this is an Antelope's 120€ product.

Anyways BTR15 sounds excellent, it has impressed me imenselly and even worked great for music production.

There's no need to have the best there is when you're so satisfied with the experience, but todays second comparison with Zen GO left me depressed. lol

 

[FiiO]

I decided to repost my report, because I suspect Fiio didn't see it (too many posts on the thread, maybe).

Can you please address the abovementioned issue on the BTR15 with your engineers?

If you already seen it and reported it to them, do you have any news about it? Thank you for your time!

Dear friend,

Yes, I have reported to them a few time. But we are sorry that we still fails to reproduce. The engineer told me that they will try to do more test first.
We apologize for any inconvenience in the meantime!

Best regards

 

[FiiO]

Hi Fiio,

maybe i have some news that could help your engineers:

i was experimenting the last couple of days and found out, that when the BTR15 is connected to my btr30 pro via bluetoth ldac and my S20FE has Bluetooth enabled the permanent reboots occur about 4-5 times per hour. It doesnt matter if the BTR 15 is connected to the samsung as a secondary device or not. As long as the S20fe has bluetooth enabled, the issue happens.
But when i disable bluetooth of the samsung while connected to the btr30pro the reboots only appear about 2 times in 12 hours.

So i assume reboots are triggered by any kind of BT packets devices send from time to time when looking for other BT devices. Hope that helps.

Dear friend,

Thanks for the kind feedback. I will report to the engineer again and hope they could locate and fix the problem soon.

Best regards